Learning spillovers in the production of EPROMs areinvestigated. It turns out that spillovers aresignificant, even though internal learning is thepredominant source of learning. Concerning externallearning, it does not appear to particularly matterwhether this comes from domestic rivals or foreigncompanies. There is some indication that Japanesecompanies have a steeper learning curve and with somegenerations are better able to appropriate externallearning from foreigners. Intergenerational learningis pervasive, which seems to provide competitiveadvantages to first movers. It could explain thepersistence of leadership of Intel in this industryacross a series of generations. Moreover, it coulddeliver scope for policy intervention.